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tesseract/ccstruct/blobbox.cpp

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/**********************************************************************
* File: blobbox.cpp (Formerly blobnbox.c)
* Description: Code for the textord blob class.
* Author: Ray Smith
* Created: Thu Jul 30 09:08:51 BST 1992
*
* (C) Copyright 1992, Hewlett-Packard Ltd.
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
** http://www.apache.org/licenses/LICENSE-2.0
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*
**********************************************************************/
#include "mfcpch.h"
#include "blobbox.h"
#include "helpers.h"
#define PROJECTION_MARGIN 10 //arbitrary
#define EXTERN
ELISTIZE (BLOBNBOX) ELIST2IZE (TO_ROW) ELISTIZE (TO_BLOCK)
// Upto 30 degrees is allowed for rotations of diacritic blobs.
const double kCosSmallAngle = 0.866;
// Min aspect ratio for a joined word to indicate an obvious flow direction.
const double kDefiniteAspectRatio = 2.0;
// Multiple of short length in perimeter to make a joined word.
const double kComplexShapePerimeterRatio = 1.5;
// Min multiple of linesize for medium-sized blobs in ReFilterBlobs.
const double kMinMediumSizeRatio = 0.25;
// Max multiple of linesize for medium-sized blobs in ReFilterBlobs.
const double kMaxMediumSizeRatio = 4.0;
// Rotates the box and the underlying blob.
void BLOBNBOX::rotate(FCOORD rotation) {
cblob_ptr->rotate(rotation);
rotate_box(rotation);
compute_bounding_box();
}
// Reflect the box in the y-axis, leaving the underlying blob untouched.
void BLOBNBOX::reflect_box_in_y_axis() {
int left = -box.right();
box.set_right(-box.left());
box.set_left(left);
}
// Rotates the box by the angle given by rotation.
// If the blob is a diacritic, then only small rotations for skew
// correction can be applied.
void BLOBNBOX::rotate_box(FCOORD rotation) {
if (IsDiacritic()) {
ASSERT_HOST(rotation.x() >= kCosSmallAngle)
ICOORD top_pt((box.left() + box.right()) / 2, base_char_top_);
ICOORD bottom_pt(top_pt.x(), base_char_bottom_);
top_pt.rotate(rotation);
base_char_top_ = top_pt.y();
bottom_pt.rotate(rotation);
base_char_bottom_ = bottom_pt.y();
box.rotate(rotation);
} else {
box.rotate(rotation);
set_diacritic_box(box);
}
}
/**********************************************************************
* BLOBNBOX::merge
*
* Merge this blob with the given blob, which should be after this.
**********************************************************************/
void BLOBNBOX::merge( //merge blobs
BLOBNBOX *nextblob //blob to join with
) {
box += nextblob->box; //merge boxes
set_diacritic_box(box);
nextblob->joined = TRUE;
}
// Merge this with other, taking the outlines from other.
// Other is not deleted, but left for the caller to handle.
void BLOBNBOX::really_merge(BLOBNBOX* other) {
if (cblob_ptr != NULL && other->cblob_ptr != NULL) {
C_OUTLINE_IT ol_it(cblob_ptr->out_list());
ol_it.add_list_after(other->cblob_ptr->out_list());
}
compute_bounding_box();
}
/**********************************************************************
* BLOBNBOX::chop
*
* Chop this blob into equal sized pieces using the x height as a guide.
* The blob is not actually chopped. Instead, fake blobs are inserted
* with the relevant bounding boxes.
**********************************************************************/
void BLOBNBOX::chop( //chop blobs
BLOBNBOX_IT *start_it, //location of this
BLOBNBOX_IT *end_it, //iterator
FCOORD rotation, //for landscape
float xheight //of line
) {
inT16 blobcount; //no of blobs
BLOBNBOX *newblob; //fake blob
BLOBNBOX *blob; //current blob
inT16 blobindex; //number of chop
inT16 leftx; //left edge of blob
float blobwidth; //width of each
float rightx; //right edge to scan
float ymin, ymax; //limits of new blob
float test_ymin, test_ymax; //limits of part blob
ICOORD bl, tr; //corners of box
BLOBNBOX_IT blob_it; //blob iterator
//get no of chops
blobcount = (inT16) floor (box.width () / xheight);
if (blobcount > 1 && cblob_ptr != NULL) {
//width of each
blobwidth = (float) (box.width () + 1) / blobcount;
for (blobindex = blobcount - 1, rightx = box.right ();
blobindex >= 0; blobindex--, rightx -= blobwidth) {
ymin = (float) MAX_INT32;
ymax = (float) -MAX_INT32;
blob_it = *start_it;
do {
blob = blob_it.data ();
find_cblob_vlimits(blob->cblob_ptr, rightx - blobwidth,
rightx,
/*rotation, */ test_ymin, test_ymax);
blob_it.forward ();
UpdateRange(test_ymin, test_ymax, &ymin, &ymax);
}
while (blob != end_it->data ());
if (ymin < ymax) {
leftx = (inT16) floor (rightx - blobwidth);
if (leftx < box.left ())
leftx = box.left (); //clip to real box
bl = ICOORD (leftx, (inT16) floor (ymin));
tr = ICOORD ((inT16) ceil (rightx), (inT16) ceil (ymax));
if (blobindex == 0)
box = TBOX (bl, tr); //change box
else {
newblob = new BLOBNBOX;
//box is all it has
newblob->box = TBOX (bl, tr);
//stay on current
newblob->base_char_top_ = tr.y();
newblob->base_char_bottom_ = bl.y();
end_it->add_after_stay_put (newblob);
}
}
}
}
}
// Returns the box gaps between this and its neighbours_ in an array
// indexed by BlobNeighbourDir.
void BLOBNBOX::NeighbourGaps(int gaps[BND_COUNT]) const {
for (int dir = 0; dir < BND_COUNT; ++dir) {
gaps[dir] = MAX_INT16;
BLOBNBOX* neighbour = neighbours_[dir];
if (neighbour != NULL) {
TBOX n_box = neighbour->bounding_box();
if (dir == BND_LEFT || dir == BND_RIGHT) {
gaps[dir] = box.x_gap(n_box);
} else {
gaps[dir] = box.y_gap(n_box);
}
}
}
}
// Returns the min and max horizontal and vertical gaps (from NeighbourGaps)
// modified so that if the max exceeds the max dimension of the blob, and
// the min is less, the max is replaced with the min.
// The objective is to catch cases where there is only a single neighbour
// and avoid reporting the other gap as a ridiculously large number
void BLOBNBOX::MinMaxGapsClipped(int* h_min, int* h_max,
int* v_min, int* v_max) const {
int max_dimension = MAX(box.width(), box.height());
int gaps[BND_COUNT];
NeighbourGaps(gaps);
*h_min = MIN(gaps[BND_LEFT], gaps[BND_RIGHT]);
*h_max = MAX(gaps[BND_LEFT], gaps[BND_RIGHT]);
if (*h_max > max_dimension && *h_min < max_dimension) *h_max = *h_min;
*v_min = MIN(gaps[BND_ABOVE], gaps[BND_BELOW]);
*v_max = MAX(gaps[BND_ABOVE], gaps[BND_BELOW]);
if (*v_max > max_dimension && *v_min < max_dimension) *v_max = *v_min;
}
// NULLs out any neighbours that are DeletableNoise to remove references.
void BLOBNBOX::CleanNeighbours() {
for (int dir = 0; dir < BND_COUNT; ++dir) {
BLOBNBOX* neighbour = neighbours_[dir];
if (neighbour != NULL && neighbour->DeletableNoise()) {
neighbours_[dir] = NULL;
good_stroke_neighbours_[dir] = false;
}
}
}
// Returns positive if there is at least one side neighbour that has a similar
// stroke width and is not on the other side of a rule line.
int BLOBNBOX::GoodTextBlob() const {
int score = 0;
for (int dir = 0; dir < BND_COUNT; ++dir) {
BlobNeighbourDir bnd = static_cast<BlobNeighbourDir>(dir);
if (good_stroke_neighbour(bnd))
++score;
}
return score;
}
// Returns the number of side neighbours that are of type BRT_NOISE.
int BLOBNBOX::NoisyNeighbours() const {
int count = 0;
for (int dir = 0; dir < BND_COUNT; ++dir) {
BlobNeighbourDir bnd = static_cast<BlobNeighbourDir>(dir);
BLOBNBOX* blob = neighbour(bnd);
if (blob != NULL && blob->region_type() == BRT_NOISE)
++count;
}
return count;
}
// Returns true, and sets vert_possible/horz_possible if the blob has some
// feature that makes it individually appear to flow one way.
// eg if it has a high aspect ratio, yet has a complex shape, such as a
// joined word in Latin, Arabic, or Hindi, rather than being a -, I, l, 1 etc.
bool BLOBNBOX::DefiniteIndividualFlow() {
int box_perimeter = 2 * (box.height() + box.width());
if (box.width() > box.height() * kDefiniteAspectRatio) {
// Attempt to distinguish a wide joined word from a dash.
// If it is a dash, then its perimeter is approximately
// 2 * (box width + stroke width), but more if the outline is noisy,
// so perimeter - 2*(box width + stroke width) should be close to zero.
// A complex shape such as a joined word should have a much larger value.
int perimeter = cblob()->perimeter();
if (vert_stroke_width() > 0)
perimeter -= 2 * vert_stroke_width();
else
perimeter -= 4 * cblob()->area() / perimeter;
perimeter -= 2 * box.width();
// Use a multiple of the box perimeter as a threshold.
if (perimeter > kComplexShapePerimeterRatio * box_perimeter) {
set_vert_possible(false);
set_horz_possible(true);
return true;
}
}
if (box.height() > box.width() * kDefiniteAspectRatio) {
// As above, but for a putative vertical word vs a I/1/l.
int perimeter = cblob()->perimeter();
if (horz_stroke_width() > 0)
perimeter -= 2 * horz_stroke_width();
else
perimeter -= 4 * cblob()->area() / perimeter;
perimeter -= 2 * box.height();
if (perimeter > kComplexShapePerimeterRatio * box_perimeter) {
set_vert_possible(true);
set_horz_possible(false);
return true;
}
}
return false;
}
// Returns true if there is no tabstop violation in merging this and other.
bool BLOBNBOX::ConfirmNoTabViolation(const BLOBNBOX& other) const {
if (box.left() < other.box.left() && box.left() < other.left_rule_)
return false;
if (other.box.left() < box.left() && other.box.left() < left_rule_)
return false;
if (box.right() > other.box.right() && box.right() > other.right_rule_)
return false;
if (other.box.right() > box.right() && other.box.right() > right_rule_)
return false;
return true;
}
// Returns true if other has a similar stroke width to this.
bool BLOBNBOX::MatchingStrokeWidth(const BLOBNBOX& other,
double fractional_tolerance,
double constant_tolerance) const {
// The perimeter-based width is used as a backup in case there is
// no information in the blob.
double p_width = area_stroke_width();
double n_p_width = other.area_stroke_width();
float h_tolerance = horz_stroke_width_ * fractional_tolerance
+ constant_tolerance;
float v_tolerance = vert_stroke_width_ * fractional_tolerance
+ constant_tolerance;
double p_tolerance = p_width * fractional_tolerance
+ constant_tolerance;
bool h_zero = horz_stroke_width_ == 0.0f || other.horz_stroke_width_ == 0.0f;
bool v_zero = vert_stroke_width_ == 0.0f || other.vert_stroke_width_ == 0.0f;
bool h_ok = !h_zero && NearlyEqual(horz_stroke_width_,
other.horz_stroke_width_, h_tolerance);
bool v_ok = !v_zero && NearlyEqual(vert_stroke_width_,
other.vert_stroke_width_, v_tolerance);
bool p_ok = h_zero && v_zero && NearlyEqual(p_width, n_p_width, p_tolerance);
// For a match, at least one of the horizontal and vertical widths
// must match, and the other one must either match or be zero.
// Only if both are zero will we look at the perimeter metric.
return p_ok || ((v_ok || h_ok) && (h_ok || h_zero) && (v_ok || v_zero));
}
// Returns a bounding box of the outline contained within the
// given horizontal range.
TBOX BLOBNBOX::BoundsWithinLimits(int left, int right) {
FCOORD no_rotation(1.0f, 0.0f);
float top = box.top();
float bottom = box.bottom();
if (cblob_ptr != NULL) {
find_cblob_limits(cblob_ptr, static_cast<float>(left),
static_cast<float>(right), no_rotation,
bottom, top);
}
if (top < bottom) {
top = box.top();
bottom = box.bottom();
}
FCOORD bot_left(left, bottom);
FCOORD top_right(right, top);
TBOX shrunken_box(bot_left);
TBOX shrunken_box2(top_right);
shrunken_box += shrunken_box2;
return shrunken_box;
}
// Helper to call CleanNeighbours on all blobs on the list.
void BLOBNBOX::CleanNeighbours(BLOBNBOX_LIST* blobs) {
BLOBNBOX_IT blob_it(blobs);
for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
blob_it.data()->CleanNeighbours();
}
}
// Helper to delete all the deletable blobs on the list.
void BLOBNBOX::DeleteNoiseBlobs(BLOBNBOX_LIST* blobs) {
BLOBNBOX_IT blob_it(blobs);
for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
BLOBNBOX* blob = blob_it.data();
if (blob->DeletableNoise()) {
delete blob->cblob();
delete blob_it.extract();
}
}
}
#ifndef GRAPHICS_DISABLED
// Helper to draw all the blobs on the list in the given body_colour,
// with child outlines in the child_colour.
void BLOBNBOX::PlotBlobs(BLOBNBOX_LIST* list,
ScrollView::Color body_colour,
ScrollView::Color child_colour,
ScrollView* win) {
BLOBNBOX_IT it(list);
for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
it.data()->plot(win, body_colour, child_colour);
}
}
// Helper to draw only DeletableNoise blobs (unowned, BRT_NOISE) on the
// given list in the given body_colour, with child outlines in the
// child_colour.
void BLOBNBOX::PlotNoiseBlobs(BLOBNBOX_LIST* list,
ScrollView::Color body_colour,
ScrollView::Color child_colour,
ScrollView* win) {
BLOBNBOX_IT it(list);
for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
BLOBNBOX* blob = it.data();
if (blob->DeletableNoise())
blob->plot(win, body_colour, child_colour);
}
}
ScrollView::Color BLOBNBOX::TextlineColor(BlobRegionType region_type,
BlobTextFlowType flow_type) {
switch (region_type) {
case BRT_HLINE:
return ScrollView::BROWN;
case BRT_VLINE:
return ScrollView::DARK_GREEN;
case BRT_RECTIMAGE:
return ScrollView::RED;
case BRT_POLYIMAGE:
return ScrollView::ORANGE;
case BRT_UNKNOWN:
return flow_type == BTFT_NONTEXT ? ScrollView::CYAN : ScrollView::WHITE;
case BRT_VERT_TEXT:
if (flow_type == BTFT_STRONG_CHAIN || flow_type == BTFT_TEXT_ON_IMAGE)
return ScrollView::GREEN;
if (flow_type == BTFT_CHAIN)
return ScrollView::LIME_GREEN;
return ScrollView::YELLOW;
case BRT_TEXT:
if (flow_type == BTFT_STRONG_CHAIN)
return ScrollView::BLUE;
if (flow_type == BTFT_TEXT_ON_IMAGE)
return ScrollView::LIGHT_BLUE;
if (flow_type == BTFT_CHAIN)
return ScrollView::MEDIUM_BLUE;
if (flow_type == BTFT_LEADER)
return ScrollView::WHEAT;
if (flow_type == BTFT_NONTEXT)
return ScrollView::PINK;
return ScrollView::MAGENTA;
default:
return ScrollView::GREY;
}
}
// Keep in sync with BlobRegionType.
ScrollView::Color BLOBNBOX::BoxColor() const {
return TextlineColor(region_type_, flow_);
}
#endif
/**********************************************************************
* find_cblob_limits
*
* Scan the outlines of the cblob to locate the y min and max
* between the given x limits.
**********************************************************************/
void find_cblob_limits( //get y limits
C_BLOB *blob, //blob to search
float leftx, //x limits
float rightx,
FCOORD rotation, //for landscape
float &ymin, //output y limits
float &ymax) {
inT16 stepindex; //current point
ICOORD pos; //current coords
ICOORD vec; //rotated step
C_OUTLINE *outline; //current outline
//outlines
C_OUTLINE_IT out_it = blob->out_list ();
ymin = (float) MAX_INT32;
ymax = (float) -MAX_INT32;
for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
outline = out_it.data ();
pos = outline->start_pos (); //get coords
pos.rotate (rotation);
for (stepindex = 0; stepindex < outline->pathlength (); stepindex++) {
//inside
if (pos.x () >= leftx && pos.x () <= rightx) {
UpdateRange(pos.y(), &ymin, &ymax);
}
vec = outline->step (stepindex);
vec.rotate (rotation);
pos += vec; //move to next
}
}
}
/**********************************************************************
* find_cblob_vlimits
*
* Scan the outlines of the cblob to locate the y min and max
* between the given x limits.
**********************************************************************/
void find_cblob_vlimits( //get y limits
C_BLOB *blob, //blob to search
float leftx, //x limits
float rightx,
float &ymin, //output y limits
float &ymax) {
inT16 stepindex; //current point
ICOORD pos; //current coords
ICOORD vec; //rotated step
C_OUTLINE *outline; //current outline
//outlines
C_OUTLINE_IT out_it = blob->out_list ();
ymin = (float) MAX_INT32;
ymax = (float) -MAX_INT32;
for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
outline = out_it.data ();
pos = outline->start_pos (); //get coords
for (stepindex = 0; stepindex < outline->pathlength (); stepindex++) {
//inside
if (pos.x () >= leftx && pos.x () <= rightx) {
UpdateRange(pos.y(), &ymin, &ymax);
}
vec = outline->step (stepindex);
pos += vec; //move to next
}
}
}
/**********************************************************************
* find_cblob_hlimits
*
* Scan the outlines of the cblob to locate the x min and max
* between the given y limits.
**********************************************************************/
void find_cblob_hlimits( //get x limits
C_BLOB *blob, //blob to search
float bottomy, //y limits
float topy,
float &xmin, //output x limits
float &xmax) {
inT16 stepindex; //current point
ICOORD pos; //current coords
ICOORD vec; //rotated step
C_OUTLINE *outline; //current outline
//outlines
C_OUTLINE_IT out_it = blob->out_list ();
xmin = (float) MAX_INT32;
xmax = (float) -MAX_INT32;
for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
outline = out_it.data ();
pos = outline->start_pos (); //get coords
for (stepindex = 0; stepindex < outline->pathlength (); stepindex++) {
//inside
if (pos.y () >= bottomy && pos.y () <= topy) {
UpdateRange(pos.x(), &xmin, &xmax);
}
vec = outline->step (stepindex);
pos += vec; //move to next
}
}
}
/**********************************************************************
* crotate_cblob
*
* Rotate the copy by the given vector and return a C_BLOB.
**********************************************************************/
C_BLOB *crotate_cblob( //rotate it
C_BLOB *blob, //blob to search
FCOORD rotation //for landscape
) {
C_OUTLINE_LIST out_list; //output outlines
//input outlines
C_OUTLINE_IT in_it = blob->out_list ();
//output outlines
C_OUTLINE_IT out_it = &out_list;
for (in_it.mark_cycle_pt (); !in_it.cycled_list (); in_it.forward ()) {
out_it.add_after_then_move (new C_OUTLINE (in_it.data (), rotation));
}
return new C_BLOB (&out_list);
}
/**********************************************************************
* box_next
*
* Compute the bounding box of this blob with merging of x overlaps
* but no pre-chopping.
* Then move the iterator on to the start of the next blob.
**********************************************************************/
TBOX box_next( //get bounding box
BLOBNBOX_IT *it //iterator to blobds
) {
BLOBNBOX *blob; //current blob
TBOX result; //total box
blob = it->data ();
result = blob->bounding_box ();
do {
it->forward ();
blob = it->data ();
if (blob->cblob() == NULL)
//was pre-chopped
result += blob->bounding_box ();
}
//until next real blob
while ((blob->cblob() == NULL) || blob->joined_to_prev());
return result;
}
/**********************************************************************
* box_next_pre_chopped
*
* Compute the bounding box of this blob with merging of x overlaps
* but WITH pre-chopping.
* Then move the iterator on to the start of the next pre-chopped blob.
**********************************************************************/
TBOX box_next_pre_chopped( //get bounding box
BLOBNBOX_IT *it //iterator to blobds
) {
BLOBNBOX *blob; //current blob
TBOX result; //total box
blob = it->data ();
result = blob->bounding_box ();
do {
it->forward ();
blob = it->data ();
}
//until next real blob
while (blob->joined_to_prev ());
return result;
}
/**********************************************************************
* TO_ROW::TO_ROW
*
* Constructor to make a row from a blob.
**********************************************************************/
TO_ROW::TO_ROW ( //constructor
BLOBNBOX * blob, //first blob
float top, //corrected top
float bottom, //of row
float row_size //ideal
) {
clear();
y_min = bottom;
y_max = top;
initial_y_min = bottom;
float diff; //in size
BLOBNBOX_IT it = &blobs; //list of blobs
it.add_to_end (blob);
diff = top - bottom - row_size;
if (diff > 0) {
y_max -= diff / 2;
y_min += diff / 2;
}
//very small object
else if ((top - bottom) * 3 < row_size) {
diff = row_size / 3 + bottom - top;
y_max += diff / 2;
y_min -= diff / 2;
}
}
/**********************************************************************
* TO_ROW:add_blob
*
* Add the blob to the end of the row.
**********************************************************************/
void TO_ROW::add_blob( //constructor
BLOBNBOX *blob, //first blob
float top, //corrected top
float bottom, //of row
float row_size //ideal
) {
float allowed; //allowed expansion
float available; //expansion
BLOBNBOX_IT it = &blobs; //list of blobs
it.add_to_end (blob);
allowed = row_size + y_min - y_max;
if (allowed > 0) {
available = top > y_max ? top - y_max : 0;
if (bottom < y_min)
//total available
available += y_min - bottom;
if (available > 0) {
available += available; //do it gradually
if (available < allowed)
available = allowed;
if (bottom < y_min)
y_min -= (y_min - bottom) * allowed / available;
if (top > y_max)
y_max += (top - y_max) * allowed / available;
}
}
}
/**********************************************************************
* TO_ROW:insert_blob
*
* Add the blob to the row in the correct position.
**********************************************************************/
void TO_ROW::insert_blob( //constructor
BLOBNBOX *blob //first blob
) {
BLOBNBOX_IT it = &blobs; //list of blobs
if (it.empty ())
it.add_before_then_move (blob);
else {
it.mark_cycle_pt ();
while (!it.cycled_list ()
&& it.data ()->bounding_box ().left () <=
blob->bounding_box ().left ())
it.forward ();
if (it.cycled_list ())
it.add_to_end (blob);
else
it.add_before_stay_put (blob);
}
}
/**********************************************************************
* TO_ROW::compute_vertical_projection
*
* Compute the vertical projection of a TO_ROW from its blobs.
**********************************************************************/
void TO_ROW::compute_vertical_projection() { //project whole row
TBOX row_box; //bound of row
BLOBNBOX *blob; //current blob
TBOX blob_box; //bounding box
BLOBNBOX_IT blob_it = blob_list ();
if (blob_it.empty ())
return;
row_box = blob_it.data ()->bounding_box ();
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list (); blob_it.forward ())
row_box += blob_it.data ()->bounding_box ();
projection.set_range (row_box.left () - PROJECTION_MARGIN,
row_box.right () + PROJECTION_MARGIN);
projection_left = row_box.left () - PROJECTION_MARGIN;
projection_right = row_box.right () + PROJECTION_MARGIN;
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list (); blob_it.forward ()) {
blob = blob_it.data();
if (blob->cblob() != NULL)
vertical_cblob_projection(blob->cblob(), &projection);
}
}
/**********************************************************************
* TO_ROW::clear
*
* Zero out all scalar members.
**********************************************************************/
void TO_ROW::clear() {
all_caps = 0;
used_dm_model = 0;
projection_left = 0;
projection_right = 0;
pitch_decision = PITCH_DUNNO;
fixed_pitch = 0.0;
fp_space = 0.0;
fp_nonsp = 0.0;
pr_space = 0.0;
pr_nonsp = 0.0;
spacing = 0.0;
xheight = 0.0;
xheight_evidence = 0;
body_size = 0.0;
ascrise = 0.0;
descdrop = 0.0;
min_space = 0;
max_nonspace = 0;
space_threshold = 0;
kern_size = 0.0;
space_size = 0.0;
y_min = 0.0;
y_max = 0.0;
initial_y_min = 0.0;
m = 0.0;
c = 0.0;
error = 0.0;
para_c = 0.0;
para_error = 0.0;
y_origin = 0.0;
credibility = 0.0;
num_repeated_sets_ = -1;
}
/**********************************************************************
* vertical_cblob_projection
*
* Compute the vertical projection of a cblob from its outlines
* and add to the given STATS.
**********************************************************************/
void vertical_cblob_projection( //project outlines
C_BLOB *blob, //blob to project
STATS *stats //output
) {
//outlines of blob
C_OUTLINE_IT out_it = blob->out_list ();
for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
vertical_coutline_projection (out_it.data (), stats);
}
}
/**********************************************************************
* vertical_coutline_projection
*
* Compute the vertical projection of a outline from its outlines
* and add to the given STATS.
**********************************************************************/
void vertical_coutline_projection( //project outlines
C_OUTLINE *outline, //outline to project
STATS *stats //output
) {
ICOORD pos; //current point
ICOORD step; //edge step
inT32 length; //of outline
inT16 stepindex; //current step
C_OUTLINE_IT out_it = outline->child ();
pos = outline->start_pos ();
length = outline->pathlength ();
for (stepindex = 0; stepindex < length; stepindex++) {
step = outline->step (stepindex);
if (step.x () > 0) {
stats->add (pos.x (), -pos.y ());
} else if (step.x () < 0) {
stats->add (pos.x () - 1, pos.y ());
}
pos += step;
}
for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
vertical_coutline_projection (out_it.data (), stats);
}
}
/**********************************************************************
* TO_BLOCK::TO_BLOCK
*
* Constructor to make a TO_BLOCK from a real block.
**********************************************************************/
TO_BLOCK::TO_BLOCK( //make a block
BLOCK *src_block //real block
) {
clear();
block = src_block;
}
static void clear_blobnboxes(BLOBNBOX_LIST* boxes) {
BLOBNBOX_IT it = boxes;
// A BLOBNBOX generally doesn't own its blobs, so if they do, you
// have to delete them explicitly.
for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
BLOBNBOX* box = it.data();
if (box->cblob() != NULL)
delete box->cblob();
}
}
/**********************************************************************
* TO_BLOCK::clear
*
* Zero out all scalar members.
**********************************************************************/
void TO_BLOCK::clear() {
block = NULL;
pitch_decision = PITCH_DUNNO;
line_spacing = 0.0;
line_size = 0.0;
max_blob_size = 0.0;
baseline_offset = 0.0;
xheight = 0.0;
fixed_pitch = 0.0;
kern_size = 0.0;
space_size = 0.0;
min_space = 0;
max_nonspace = 0;
fp_space = 0.0;
fp_nonsp = 0.0;
pr_space = 0.0;
pr_nonsp = 0.0;
key_row = NULL;
}
TO_BLOCK::~TO_BLOCK() {
// Any residual BLOBNBOXes at this stage own their blobs, so delete them.
clear_blobnboxes(&blobs);
clear_blobnboxes(&underlines);
clear_blobnboxes(&noise_blobs);
clear_blobnboxes(&small_blobs);
clear_blobnboxes(&large_blobs);
}
// Helper function to divide the input blobs over noise, small, medium
// and large lists. Blobs small in height and (small in width or large in width)
// go in the noise list. Dash (-) candidates go in the small list, and
// medium and large are by height.
// SIDE-EFFECT: reset all blobs to initial state by calling Init().
static void SizeFilterBlobs(int min_height, int max_height,
BLOBNBOX_LIST* src_list,
BLOBNBOX_LIST* noise_list,
BLOBNBOX_LIST* small_list,
BLOBNBOX_LIST* medium_list,
BLOBNBOX_LIST* large_list) {
BLOBNBOX_IT noise_it(noise_list);
BLOBNBOX_IT small_it(small_list);
BLOBNBOX_IT medium_it(medium_list);
BLOBNBOX_IT large_it(large_list);
for (BLOBNBOX_IT src_it(src_list); !src_it.empty(); src_it.forward()) {
BLOBNBOX* blob = src_it.extract();
blob->ReInit();
int width = blob->bounding_box().width();
int height = blob->bounding_box().height();
if (height < min_height &&
(width < min_height || width > max_height))
noise_it.add_after_then_move(blob);
else if (height > max_height)
large_it.add_after_then_move(blob);
else if (height < min_height)
small_it.add_after_then_move(blob);
else
medium_it.add_after_then_move(blob);
}
}
// Reorganize the blob lists with a different definition of small, medium
// and large, compared to the original definition.
// Height is still the primary filter key, but medium width blobs of small
// height become small, and very wide blobs of small height stay noise, along
// with small dot-shaped blobs.
void TO_BLOCK::ReSetAndReFilterBlobs() {
int min_height = IntCastRounded(kMinMediumSizeRatio * line_size);
int max_height = IntCastRounded(kMaxMediumSizeRatio * line_size);
BLOBNBOX_LIST noise_list;
BLOBNBOX_LIST small_list;
BLOBNBOX_LIST medium_list;
BLOBNBOX_LIST large_list;
SizeFilterBlobs(min_height, max_height, &blobs,
&noise_list, &small_list, &medium_list, &large_list);
SizeFilterBlobs(min_height, max_height, &large_blobs,
&noise_list, &small_list, &medium_list, &large_list);
SizeFilterBlobs(min_height, max_height, &small_blobs,
&noise_list, &small_list, &medium_list, &large_list);
SizeFilterBlobs(min_height, max_height, &noise_blobs,
&noise_list, &small_list, &medium_list, &large_list);
BLOBNBOX_IT blob_it(&blobs);
blob_it.add_list_after(&medium_list);
blob_it.set_to_list(&large_blobs);
blob_it.add_list_after(&large_list);
blob_it.set_to_list(&small_blobs);
blob_it.add_list_after(&small_list);
blob_it.set_to_list(&noise_blobs);
blob_it.add_list_after(&noise_list);
}
// Deletes noise blobs from all lists where not owned by a ColPartition.
void TO_BLOCK::DeleteUnownedNoise() {
BLOBNBOX::CleanNeighbours(&blobs);
BLOBNBOX::CleanNeighbours(&small_blobs);
BLOBNBOX::CleanNeighbours(&noise_blobs);
BLOBNBOX::CleanNeighbours(&large_blobs);
BLOBNBOX::DeleteNoiseBlobs(&blobs);
BLOBNBOX::DeleteNoiseBlobs(&small_blobs);
BLOBNBOX::DeleteNoiseBlobs(&noise_blobs);
BLOBNBOX::DeleteNoiseBlobs(&large_blobs);
}
#ifndef GRAPHICS_DISABLED
// Draw the noise blobs from all lists in red.
void TO_BLOCK::plot_noise_blobs(ScrollView* win) {
BLOBNBOX::PlotNoiseBlobs(&noise_blobs, ScrollView::RED, ScrollView::RED, win);
BLOBNBOX::PlotNoiseBlobs(&small_blobs, ScrollView::RED, ScrollView::RED, win);
BLOBNBOX::PlotNoiseBlobs(&large_blobs, ScrollView::RED, ScrollView::RED, win);
BLOBNBOX::PlotNoiseBlobs(&blobs, ScrollView::RED, ScrollView::RED, win);
}
// Draw the blobs on the various lists in the block in different colors.
void TO_BLOCK::plot_graded_blobs(ScrollView* win) {
BLOBNBOX::PlotBlobs(&noise_blobs, ScrollView::CORAL, ScrollView::BLUE, win);
BLOBNBOX::PlotBlobs(&small_blobs, ScrollView::GOLDENROD, ScrollView::YELLOW,
win);
BLOBNBOX::PlotBlobs(&large_blobs, ScrollView::DARK_GREEN, ScrollView::YELLOW,
win);
BLOBNBOX::PlotBlobs(&blobs, ScrollView::WHITE, ScrollView::BROWN, win);
}
/**********************************************************************
* plot_blob_list
*
* Draw a list of blobs.
**********************************************************************/
void plot_blob_list(ScrollView* win, // window to draw in
BLOBNBOX_LIST *list, // blob list
ScrollView::Color body_colour, // colour to draw
ScrollView::Color child_colour) { // colour of child
BLOBNBOX_IT it = list;
for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
it.data()->plot(win, body_colour, child_colour);
}
}
#endif // GRAPHICS_DISABLED
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